Every morning, dozens of customers line up outside the doors of Last Place on Earth so they can buy fake pot and other synthetic drugs as soon as the store opens at 10 a.m.

They are drawn to this old brick building because they know the head shop is one of the last places in Minnesota that openly sells the sometimes deadly substances despite a July 1 ban on synthetic drugs.

Some come from the Twin Cities, according to owner Jim Carlson. Others travel even farther. On Friday, a trucker from Grand Rapids, Minn., said he started making the 80-mile drive to Carlson's store every three weeks because his neighborhood smoke shop stopped selling "herbal incense."

Duluth resident Heidi Middleton, who was first in line, said she comes almost every day. "If I don't have weed in my system, I go into convulsions and throw up," said Middleton, 38. "It mellows me out."

Any day now, Carlson predicts, police will raid the shop he's owned for 29 years and arrest him. But every day that doesn't happen puts another $16,000 or so in his till, Carlson estimates. That means the small, crowded shop is hauling in almost $6 million a year from synthetic marijuana and stimulants.

Local officials, who have tried in vain for years to force Carlson to stop selling drug-related merchandise, think the retailer has gone way too far this time.

"He flaunts and he taunts, and I think it's absolutely disgusting how you can sell a product to people that damages users and innocent bystanders," Duluth City Council Member Todd Fedora said.

Last year, Fedora spearheaded an effort to make Duluth the first city in the state to ban synthetic pot. But the city stopped trying to enforce the ordinance after Carlson threatened to hold the city responsible for his economic losses in a federal lawsuit that claimed the rule was unconstitutionally broad.

Duluth Police Chief Gordon Ramsay said Carlson is on his radar. "We're aware of the problem and are working on it," Ramsay told the Star Tribune Thursday.

Carlson, whose business has tripled since he started selling synthetic drugs two years ago, said he's willing to risk arrest for several reasons: The money is so good, and he believes banning drugs doesn't work and infringes on people's rights.

He also claims to have taken steps to make sure his products don't violate the state's new ban, though the results of a test conducted for the Star Tribune showed that some of his synthetic pot contained a chemical specifically outlawed in Minnesota. Carlson said his supplier made a mistake and has since switched to a legal formula.

"If I get busted, I would demand a jury trial," said Carlson, who complained Monday to the City Council that police were harassing customers in front of his store.